Optis Cellular Technology LLC & Ors v Apple Retail UK Ltd & Ors

For patent construction, “conversion” may comprise both rendering measurements comparable and expressing them in the receiving system’s format. The court must construe the term in the context of the patent as a whole. Comparability may arise through encoding or mapping and does not require arithmetic manipulation or an added offset.

A claim is not rendered obvious merely because it contains an arbitrary limitation. Under the Agrevo principle, the limitation cannot assist the patentee only if it is arbitrary; the claim must still be obvious over the prior art or common general knowledge. Where the claimed feature provides a common technical benefit across the claim’s scope, the objection fails.

This was the first trial in patent litigation between Optis and Apple concerning EP (UK) 1 230 818, entitled “Method for improving handovers between mobile communications systems”. Optis alleged that the patent was valid and essential to specified versions of the GSM standard, concerning enhanced and normal reporting of UMTS and LTE measurements.

Apple denied essentiality and alleged obviousness over Losh, Tdoc 1145/99 and the Agrevo principle, together with insufficiency based on Biogen and uncertainty. The principal issues were the construction of “conversion”, whether the relevant standards implemented the claimed method, and whether the patent was invalid.

1. Construction. The term “conversion” in claim 1 required two aspects: rendering measurements from the first communication system directly comparable with measurements in the second system, and expressing them in the second system’s measurement format. The term was construed from the patent as a whole, rather than by a narrow verbal analysis. Conversion did not require a mathematical or arithmetic operation. Encoding and mapping could make measurements comparable.
2. Essentiality. The GSM standards’ encoding of UMTS RSCP measurements into the six-bit GSM format satisfied the formatting requirement. The encoded RSCP and GSM RXLEV values were directly comparable. Offsets used in priority-level comparisons adjusted or biased results but did not create comparability. Enhanced reporting under the 2006 standard, enhanced reporting of LTE RSRP under the 2011 standard, and normal reporting under the later standard therefore fell within the claims. Claims 1, 2, 3 and 8 were essential.
3. Obviousness. Losh disclosed inter-RAT handover, threshold comparisons and reporting, but did not make conversion for comparability or GSM formatting obvious. Tdoc 1145/99 made a specific proposal centred on handover decisions in the RNC and use of the FACCH. Its alternatives did not provide an obvious route to the claimed conversion. The claims were not obvious over either reference.
4. Internal validity. Uncertainty insufficiency failed because the skilled person could understand and apply “conversion”. The Agrevo principle was general, but an arbitrary limitation alone did not invalidate a claim. Conversion was not arbitrary because it supplied common technical benefits across the claim. Biogen insufficiency also failed.
5. The claim for infringement succeeded. Apple’s counterclaim for revocation failed.